A Universal Optical Microanalysis Platform Based on Micropipette Tips

The need for automated analytical devices capable of handling low-volume samples remains a major challenge in medical diagnostics, biomedical research, and environmental studies. Although microfluidic systems have shown promise, their broader adoption has been limited by challenges such as intricate chip fabrication, cumbersome sample loading, limited detector integration, and significant dead volumes. Herein, we report a micropipette tip-based Lab-on-a-Tip platform that integrates fluid handling, reagent loading, chemical reaction, and optical detection within a single, modular unit. The system couples a low-cost multispectral photodiode directly to the pipette tip, enabling multi-channel absorbance and fluorescence measurements in a few microliters of samples. Fluid manipulation is automated using a programmable pipette, allowing chemical and biochemical assays to be conducted within pipette tips preloaded with reagents. The inherent advantages of pipette tips, such as affordability, optical clarity, solvent compatibility, precise fluid control, and flexible conical geometry, distinguish them from traditional microfluidic chips. The capability of the platform is demonstrated through a series of assays, including enzymatic reaction monitoring, biochemical sensing with molecular probes, biphasic detection with oil sensors, and multi-step chemical analyses. By streamlining workflows, minimizing reagent consumption, eliminating dead volumes, and enhancing portability, Lab-on-a-Tip offers a transformative solution for compact, high-performance analytical systems.